Urban Heatwave Resilience as a Social-Ecological System: Diagnosing Incremental and Transformative Policy Pathways in High-Density Cities

Intensifying urban heatwaves pose escalating risks to public health, ecosystem stability, and urban livability, yet existing urban heatwave policies continue to produce limited and short-lived outcomes (Siyu Yu et al., 2024). These recurring policy failures suggest not a lack of interventions, but structural mismatches between dominant policy logics and the underlying social–ecological dynamics that generate heat risk (Chen et al., 2024).

This study aims to explain why urban heatwave response policies repeatedly stall in many high-density inner-city contexts and examines in a smaller set of cities, by focusing on high-density inner urban areas as a representative urban type, thereby identifying where policy interventions must be directed to enable a transition toward long-term, transformative urban heatwave resilience. The study analyzes urban heatwave resilience as a social–ecological system, classifies dominant policy approaches based on their system intervention points, and derives key leverage points associated with Blue–Green Infrastructure (BGI).

A systems-based analytical framework grounded in the Social–Ecological System (SES) approach and Causal Loop Diagramming (CLD) was applied. Comparative policy analyses were conducted across high-density cities where heatwave policies have remained largely incremental—Seoul (South Korea), Tokyo (Japan), Hong Kong (China), and Paris (France)—and contrasted with cities exhibiting relatively different policy trajectories, including Singapore and Melbourne (Australia).Core reinforcing and balancing feedback loops shaping heatwave risk were identified, and dominant policy logics were mapped onto these loops to diagnose structural limitations. Meadows’ leverage points framework and concepts of transformative resilience were then applied to interpret system-level intervention pathways.

The analysis revealed that in most high-density cities heatwave policies primarily intervened in downstream outcome variables, leaving reinforcing feedback related to land use, governance fragmentation, and social vulnerability largely intact. In contrast, cities exhibiting more adaptive trajectories showed consistent interventions at higher leverage points, including planning rules, institutional coordination, information flows linking climate data to decision-making, and mechanisms of social self-organization. While no city fully resolved urban heat risk, these higher-level interventions enabled partial systemic shifts, notably in the feedback structures governing BGI integration and urban heat exposure mitigation. The contrast across cases demonstrates that differences in policy effectiveness are better explained by intervention location within the system than by policy intensity or quantity.

This study provides a structural explanation for divergent urban heatwave policy trajectories in high-density cities and reframes BGI as a transformative lever embedded within urban social–ecological systems rather than a supplementary adaptation measure. The findings offer policy-relevant insights for redirecting heatwave governance from incremental, outcome-oriented responses toward system-level interventions that support long-term, equitable urban resilience.

 

※ Acknowledgement: This work was supported by Korea Environment Industry &Technology Institute (KEITI) through "Climate Change R&D Project for New Climate Regime.", funded by Korea Ministry of Environment (MOE) (RS-2022-KE002123).